The bull gear is the largest movable (rotating) piece of the ship’s steam turbine drive train except for the propeller. It is mounted between the aft end of the turbines and the propeller shaft/thrust bearing and served as a reduction gear reducing the shaft speed to a nominal 108 RPM. This precision manufactured bull gear has a 13.5 foot diameter and a 34 inch face and weighs in at 66,000 pounds. At 108 RPM, the gear face on the bull gear was traveling at a speed of about 55 miles per hour.
The piece we obtained from the scrapper weighed about one half the entire bull gear (33,000 pounds) and includes a representative section of both the gear and the shaft keyway. We were obviously constrained from obtaining the entire piece by transportation considerations.
The bull gear was removed from the N/S SAVANNAH in the early 1990's and installed without any substantial modification in the AMERICAN EXPLORER where it sailed for several years. The EXPLORER was finally sent to the scrapper, Southern Recycling, in New Orleans. That is where we found it and thanks to Randy Boudreaux of Southern Recycling, were able to obtain this exciting piece of the ship.